Evidence from both clinical and research experience indicates that patients with sleep apnea suffer from affective distress as well as decreased efficiency in their daytime functioning. Obstructive sleep apnea (OSA) is fully reversible with continuous positive airway pressure (CPAP). This investigation is to determine which daytime sequelae of OSA are reversible with treatment. The basic design is a 2x4 mixed factorial (using Group and Time), with subjects randomly assigned to either condition in a double-blind fashion.